Modern methods in carbohydrate synthesis

Biochimie (1997) 79, 309-311 © Social6 fi'an~-ifise de biochimie el biologie mol6culaire I Elsevier, Paris

Phytochemical Divcrsily and Redundancy in Ecological Interactions, edited by IT Rom6o, JA Saunders, P Barbosa, Plenum Press, 1996, $89.50, 319 p As we approach the 21st century, there is an increasing concern about biodiversity and ecological phytochemistry with hopes of finding new nalural products and to obtain a better understanding of the complex lelations between plant-pest and plant-pathogen tandems. This latter subject has been addressed from a fundamental point of view in an excellent muitiauthored book Phytochemical Divervitv and Retholdan¢T in EcohJgical h~ter~,ctions edited by JT Romeo, JA Saunders and P Barbosa at Plenum Press. Their book is a selected compihltion of topics presented at a synlposium of the Phytochelnicai Society of North Americlt held in August, 1995. The book cllapters are divers, but deal with the varions aspects of diversity and redundancy of plant phytochemistry in relation to defense. Some exlunples are: I) the parallels existing between insecticidal activity and defense against pathogens; 2) diversity, redundancy and multiplicity in chemical defense systems; and 3) natural products, complexity and evolution. The chapters of this book convey very convincingly that the functions of natural products are often multiple and diverse, often implicated in various forms of defense; certain natural products span species barriers and sometimes kingdom barriers. For example, the chapter on polyphenol oxidar~e as a component of the inducible defense response in tomato against herbiw)res, compares this enzyme with polyphenol oxidases in other organisms like arthropods and mammals. Alter reading a chapter like this, one gets the impression that someone working on insect phenol oxidases could discover some refreshingly new ideas to bring back into his own field. Furtherntore, this chapter and the others reflect the interest and necessity for scientists working on the same or sinlihn" products in different organisms to cross the bairriers of our narrow scientific conununities and to increase active discussion. It is perhaps via this strategy thai we will find the true functions and ewllulionary relations between naluriil liroducts. In addition to tile vasl anlount tif and inlelleclniilly siinitlhiting ~cienlilic infornlalion therein, Ihe book chapters arc very well w,.rilten, well documented and sllfficienlly itccessible to tile non°sp¢chilo isl reader, ! consider this book it inusl for enioniologists, ecologists and those hiterested in hiseci/I)hint l)athogeli/pliinl hllerilclions, The authors have enlhusJasticillly conveyed Ihal Iheh' subieci is nliiid opening iliad ¢hallenghig by its COliiplexiiy. P Brey

Modern Methods in Carbohydrate Synthesis, edited by SH Khan. RA O'Neill, Harwood Academic Publishers, 1996. $170.00. 558 p Carbohydrates play significant roles in inlpol'lant biological processes, but are diMcult to obtain in sufficient quantilies fronl natural sources. The developinent of methods allowing the eMcient construction of complex oligosilccharides has therefore becoine of great concern over the past decitdes. In this lirst volume of a series entitled 'Frontiers in Natural Product Research', the editors sought to produce a one-volume

survey of the ~elevant methodologies published in recent yee.r~, in this field, namely of the so-called "current state-of-the-art synthetic carbohydrate chemistry'. Thus, selected topics are reviewed through a compilation of 21 assays, all written by well-known authors in the field of glycobiology. As it stands, the book cornprises three ..main parts'.. i). the. stereos . pecific tbrmation of ~.elvcosidic bond; ill the construction of naturally occurring as well as unnatural sugar derivatives and glycoconjugates: and iii) the use of enzymes in oligosaccharide synthesis. An enjoyable historical overview of the rich arsenal of strategies for oligosaccharide synthesis now at hand, appropriately serves as an introduction to the whole volume. The first topic is the most extensively covered. Several chapters deal with well-established methodol,~gies. That on trichioroacetimidate glycosyl donors is especially appealing as it combines useful mechanistic insights together with representative examples of their recent applications in demanding glycoconjugate syntheses. A simihn" coverage of the synthetic use of thioglycosides and sulfoxides would have been of great value, instead the paper mainly reporls on their preparation and activation. One can regret that the chapter on glycosyl halides focuses on the use ofdihalogenomethyi methyl ethers only, but the reader will certainly appreciate the experimental details available. More recently developed methodologies are also addressed. Among these, the versatility of phenylselenoglycosides clearly appears through a good analysis of selective activation strategies. A concise description of the armed/disarmed protocol and its alternatives is provided in a chapter on the n-pentenyl methodology. Besides, possible extensions of this methociology ate introduced. For instance, enol ethers and their variations are presented in an enjoyable pedagogic nlanner. Signilicant efforts to develop an approach to solid-phase synthesis of oligosaccharides are outlined in two ways. In one case, emphasis is put on the glycal methodology and its potential both in solution and on a solid support. A second paper is devoted to polymer-supporled solution synthesis. Special attention should be paid to the latter which provides useful hints on several aspects of this cheniisiry together with detailed experinlenlal procedures, l.asl but iiol leiisl, conies a very wellodon¢ t'haplcr on pi'olcclinL~' ~,l'litii)~, it slllliiltl definitely lie read with careflll alieillion. The se~:olid se~:tioii of the hook covers, among others, solne, of tile inosi challellging carboliydrales to build, In particular, t)rt-igi'es.~ in the COllSll'UCiion of tile ~-D-nl~ulnopyrlinosidic lillk~ige ~ir~ re o ported ill both ilia iilstructive illld pleasant Wily. Coglycosides llrl2 also reviewed. Unfortunately, the doctlmeni covers the lileraitlr~ up to 1992 only, whereas work published in 1994 is cited in i.ill the other chapters (except for one). Glycoconjugate synthesis certainly is honored in the book. The most recent developments in the field of glycopeptides are exposed in a very intbrmative and attractive way. Besides, strong experilrlental support is provided. Also worth menticmo ing is a general chapter on glycopolyiners of biological inteiest. Lastly, synthetic strategies leading to biologically charged carbohydrilteS are discussed, based oil nuinea~us selected exainples. Alternative methodologies such as the enzylllatic approach are exposed in the last section o1"the book. Three chapters are devoted to glycosyltransferases and overall the material presented is of high quality. Unfortuilately. redundancies could not be avoided and sometimes an air de dejdt vu emerges from the text. An interesting manuscript conveying on synthetic applications of glycosidases concludes the update on this promising area of glycotechnology. All along this compilation of well-balanced chapters, emph;lsis is put on biologically active molecules, an editors' choice which reinlbrces the impact of the volume. Despite unaw~idable om-

310 issi~s., for instance the use of glycosyl fluorides as donors, the edilors' goals were successi~lly met. The typographical presentation is pleasant and t ~ text is supported by numerous synthetic and mechanistic .~hemes. Overall, the book should be looked at as a ~ i s t i c a t e d tool-boy Surely. it will prove to be of valuable interest to s t ~ n ~ ~ well as to more experienced scientists in the field

L Mulard

C ~ E n e y e l o ~ , Biochemistry a n d Molecular Biology, ~ i ~ ~ i t ~ n , ~vised and expanded by TA Scott a ~ E! Mercer, Walter de Gruyter, DM i 68.00, ! 997. 737 p

The second edition of the concise encyclopedia, centered on bioc~mistry was published in 1988. A little less than !0 years later we have a new edition of this encyclo~dia where molecular biology has been plac~ in the limelight. A review tbr such a book cannot be exhaustive, and it can only reflect the main interests of the reader, Did he find the inlbrmation he was looking for? Let us think ~at he is interested in intermediary metabolism: he would look Ibr 'glycolysis' or 'TCA-cycle'. The first item is there, and well documented, Unlbrtunately the second one cannot be found immediately, although it is present, and well documented, under its complete name 'tricarboxylic acid cycle, TCA-cycle'. The reader might think that I am overcritical, but when one sees a paper published in Science a few months ago, and sighted by some 40 authors, and commenting on the trichloracetic cycle (sic) of a methanogen, one is led to think thai the TCA-cycle entry should b¢ present in this encyclol~dia! But we should be fair, most of the questions that can ~ asked about intermediary metabolism, including fatty acids and lipids mela~lism have their answer there, Let us now look for th~ interests of a molecular biologist: plasmid, rep!icon, restriction ~n~yme, transli~rrnation, transi~)son, vector, etc. All these items have an entry, Could we try something more esoteric, like electa~ l~ration ? Electrophoresis is there, but not eleclroporation, This e~s~bli,s~s t l~ t~rder at which this encyclol~lia limits itself, For ra~ metabofic compout~ds, such as those that arc synthesized as s~on~ry meta~fites, this ¢ncyclol~dia pt~)vides quite a t~w entries, but, obvi(~sl~ it cannot cover the field, even in the case of antibiotics, Man), aminoglycosides arc present under the entry 'strcplomycia' and the drawing representing kanamycin is labelled kanom,vcin, In summary, this encyclo~ia can be of significant use when looking for the definition of many objects and concepts dealing with bi~hemistry and molecular biology, Its place is in laboratories which do not hax~e a convenient and quick access to a ge~ral library, AL Lecocq

George Washington University in Washington, May 6-9, 1996. The book was edited the same year, which represents an excellent adequacy between the date of the meeting and publication of the text. Most of the plenary lectures presented have been individualized in different chapters (38, in total) and the book is divided into seven parts. Although new facets dealing with lipid investigation are covered, a fair number of texts do not represent 'frontier" topics but, in the context of the present knowledge, rather a rejuvenation of aspects that have been disregarded during the recent years. A positive aspect concerns the coverage of various topics that include many aspects of ongoing front line research such as the inducible cyclooxygenase, receptors of lipid mediators, sphingolipids, phospholipids and related enzymes such as the phospholipase D pathway. Finally, the binding of fatty acids to peroxisome proliferator-activated nuclear receptors is described; however, one can regret that no report presents the interaction of arachidonic acid metabolites and this family of receptors. Other novel aspects such as the potential significance of isoprostanes, free-radical metaboiites derived from arachidonic acid have not been presented and it is not clear if such themes were not contributed during this meeting or if the manuscript was never received. The limited format of the individual chapters ends, for most of them, in a superficial presentation of the subject covered, in many aspects, it is therefore very. difficult to establish an appropriate evaluation based on the scientific contents of each section, taking in perspective what will be the impact on a 'naive' reader. In addition, the book suffers from a heterogeneity in the presentation of each individual chapter (length ranging from four to 12 pages). For instance some authors included a useless and poorly described Materials and Methods" section; usually, this is followed by a very focused presentation of their own results and own literature with little perspective of the results in the overall research area. In contrast, others (unfortunately too few) present a "state-of-the-art' format, more appropriate for this kind of book. The same remark applies to a bibliography which ranges from largely insul'ficient (as little as seven references) to satisfactory (up to approximately O0). Overall the limils of the book lay in the ambiguity of its goals, ie offering leo many Lopic.~ related to new lipids, keeping with a limited text xize and absence of strict guidelines, ie an obvious lack of clear-cut instructions to attthors combined with an absence of review of individual manuscripts. Overall, the end-result is a manual that does not cover the potentials contained in its title. It may however ~ of potential use lbr experts in the field who want to glimpse in various areas of current lipid research. In contrast, it d ~ s not constitute a shelf reference book for a neophyte trying to get introduced in some of the novel areas described here.

J Maclouf Subcellular Biochemistry (vol 27). Biology of the Lysosome, edited by JB Lloyd, RW Mason, Plenum Press, 1996, $129.50, 416 p

Frontiers in Bioactive Lipids, edited by JY Vanderhoek, Plenura Press, 19~, $1 I0, 313 p Fhmriers in Bi~lcth,e Lipid, edited by Jack Vanderhoek (Plenum I~ss), gathers texts t'a~m the proceedings of a meeting held at the

This book is a valuable manual tbr laboratories working in the areas of intracellular biology and biochemistry and is also an excellent aid for teaching graduate and undergraduate courses in cellular bit~bemistry. The topics are presented in a sequence that increases gradually in the level of complexity, so that few questions are left